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WASTE DISCHARGE REQUIREMENTS ORDER R5-2012-0105 2 <br /> DIAMOND PET FOOD PROCESSORS OF RIPON, LLC AND <br /> RIPON COGENERATION, LLC <br /> DIAMOND PET FOOD RIPON FACILITY <br /> SAN JOAQUIN COUNTY <br /> Previous Facility and Discharge <br /> 7. Neenah manufactured several grades of fine papers from purchased pulps including virgin <br /> bleached pulp, deinked post-consumer waste, and waste paper. The paper mill's <br /> maximum daily production rate was 200 tons of paper. The wastewater generated from <br /> paper processing was applied to land on the mill property. Wastewater flows to the <br /> clarifier from Neenah and Ripon Cogeneration, LLC averaged 1.0 to 2.0 mgd. <br /> 8. Prior to 2001, waste discharged to percolation areas by Neenah had TDS concentrations <br /> up to 2500 mg/L, which resulted in groundwater degradation with salinity constituents <br /> beneath the land application areas, and the Central Valley Water Board found that the <br /> past waste discharges were classified as "designated wastes" under California Code of <br /> Regulations title 27, division 3. Prior to 2001 Neenah reduced effluent TDS by: <br /> a. Reducing alum usage in the paper-making process; <br /> b. Installing a brine concentrator at the cogeneration plant and hauling the concentrated <br /> brine off-site for reuse by another company; and <br /> c. Replacing three water supply wells that were screened in the upper, intermediate and <br /> lower zones with five new water supply wells to reduce the TDS of the paper mill <br /> source water and eliminate the cross-contamination of the deeper aquifer zones. <br /> 9. The Central Valley Water Board also found that the paper mill sludge is an inert waste. <br /> Neenah completed in-place closure of the inactive sludge impoundments in accordance <br /> with an approved workplan by consolidating and dewatering the sludge and covering the <br /> areas with a one foot thick soil layer to serve as a final vegetative layer. The areas were <br /> regraded to divert storm water drainage away from the closed impoundments. <br /> Because the former sludge impoundments do not pose a threat to water quality, it is <br /> appropriate that this Order does not regulate them. <br /> 10. Ripon Cogeneration, LLC has historically discharged its cooling tower blowdown and <br /> reverse osmosis (RO) reject brine to the paper mill's wastewater treatment system under <br /> a long-term agreement with Neenah. Ripon Cogeneration, LLC's wastewater flows <br /> recently ranged between 0.2 and 0.3 mgd with an average TDS concentration of <br /> 1,000 mg/L. In the past, Ripon Cogeneration, LLC's wastewater was blended with paper <br /> mill wastewater in the clarifier before land application. The overall blended and treated <br /> wastewater had an average TDS concentration of 812 mg/L in 2008 with a range between <br /> 682 mg/L and 928 mg/L. Since the paper mill closed in May 2009, Ripon Cogeneration, <br /> LLC's cooling tower blowdown and RO reject brine have been diluted with low TDS <br /> groundwater before being discharged to the LAAs; and the effluent had an average TDS <br /> concentration of 526 mg/L from May 2010 through .Pune 2011. <br /> 11, The wastewater treatment facility consists of a solids separation system, a clarifier, two <br /> aeration stabilization basins (ASB-1 and ASB-2) operated in series, and 86 acres of <br /> percolation fields and orchards (Land Application Areas, "LAAs"). In addition, unlined <br /> Ponds 1 through 4 are used only to contain excess wastewater in case of treatment <br /> system upset or to store storm water runoff during the wet seasons. Storm water <br /> collected in the ponds is applied to the LAAs and no storm water runoff is discharged to <br /> surface waters. There are two closed paper mill sludge disposal units onsite. A site map <br />